Institut de Recerca de la Biodiversitat (IRBio) and Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, Barcelona, Spain.
PLoS One. 2018 Jun 12;13(6):e0198667. doi: 10.1371/journal.pone.0198667. eCollection 2018.
Studying the movements of oceanic migrants has been elusive until the advent of several tracking devices, such as the light-level geolocators. Stable isotope analysis (SIA) offers a complementary approach to infer areas used year-round, but its suitability in oceanic environments remains almost unexplored. To evaluate SIA as a tool for inferring movements of oceanic migrants, we sampled an oceanic seabird, the Bulwer's petrel, Bulweria bulwerii, in four breeding colonies spread along its Atlantic distribution. We first studied the species moulting pattern from 29 corpses collected in the colonies. Secondly, based on this moult knowledge, we selected three feathers from tracked birds to infer their breeding and non-breeding grounds using SIA: the 1st primary (P1), the 8th secondary (S8) and the 6th rectrix (R6) feathers. Birds migrated to two main non-breeding areas, the Central or the South Atlantic Ocean. P1 showed similar isotopic values among petrels from different breeding colonies, suggesting this feather is replaced early in the non-breeding period in a common area used by most birds, the Central Atlantic. S8 and R6 feathers correctly assigned 92% and 81%, respectively, of the birds to their non-breeding areas, suggesting they were replaced late in season, when birds were settled in their main non-breeding grounds. Our results showed that the isotopic baseline levels of the Central and South Atlantic are propagated through the food web until reaching top predators, suggesting these ratios can be used to infer the movement of long-distance migrants among oceanic water masses.
直到几种追踪设备（如光强地理定位仪）的出现，对海洋洄游生物的运动研究才变得可行。稳定同位素分析（SIA）提供了一种推断全年使用区域的补充方法，但它在海洋环境中的适用性几乎尚未得到探索。为了评估 SIA 作为推断海洋洄游生物运动的工具，我们在大西洋分布范围内的四个繁殖地采集了 Bulwer's petrel（Bulweria bulwerii）这种海洋海鸟的样本。我们首先研究了从 29 只在繁殖地收集的尸体中获得的物种换羽模式。其次，基于这种换羽知识，我们从被追踪的鸟类身上选择了三根羽毛，通过 SIA 推断它们的繁殖地和非繁殖地：第一根初级羽毛（P1）、第八根次级羽毛（S8）和第六根尾羽（R6）。鸟类迁徙到两个主要的非繁殖区，即大西洋中部或南部。P1 显示了来自不同繁殖地的海燕之间相似的同位素值，这表明这种羽毛在非繁殖期早期在大多数鸟类使用的共同区域（大西洋中部）被替换。S8 和 R6 羽毛正确地将 92%和 81%的鸟类分配到它们的非繁殖区，表明它们在季节后期被替换，此时鸟类已经在它们的主要非繁殖地定居。我们的结果表明，大西洋中部和南部的同位素基线水平通过食物网传播，直到到达顶级捕食者，这表明这些比值可用于推断海洋水团中长距离洄游生物的运动。
